#define _CRT_SECURE_NO_WARNINGS 1

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode() : val(0), next(nullptr) {}
 *     ListNode(int x) : val(x), next(nullptr) {}
 *     ListNode(int x, ListNode *next) : val(x), next(next) {}
 * };
 */
class Solution {
public:
    ListNode* rotateRight(ListNode* head, int k)
    {
        if (head == nullptr)
            return head;
        ListNode* cur = head;
        int len = 1;
        while (cur->next != nullptr)
        {
            cur = cur->next;
            len++;
        }
        cur->next = head;
        len = len - (k) % len;
        ListNode* prev = head;
        cur = head;
        while (len--)
        {
            prev = cur;
            cur = cur->next;
        }
        prev->next = nullptr;
        head = cur;
        return head;
    }
};

